1 files changed, 86 insertions, 0 deletions
diff --git a/libmisc/find_new_sub_uids.c b/libmisc/find_new_sub_uids.c
new file mode 100644
index 0000000..12cb2d2
--- /dev/null
+++ b/libmisc/find_new_sub_uids.c
@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2012 Eric Biederman
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the copyright holders or contributors may not be used to
+ *    endorse or promote products derived from this software without
+ *    specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <config.h>
+
+#ifdef ENABLE_SUBIDS
+
+#include <assert.h>
+#include <stdio.h>
+#include <errno.h>
+
+#include "prototypes.h"
+#include "subordinateio.h"
+#include "getdef.h"
+
+/*
+ * find_new_sub_uids - Find a new unused range of UIDs.
+ *
+ * If successful, find_new_sub_uids provides a range of unused
+ * user IDs in the [SUB_UID_MIN:SUB_UID_MAX] range.
+ * 
+ * Return 0 on success, -1 if no unused UIDs are available.
+ */
+int find_new_sub_uids (const char *owner,
+		       uid_t *range_start, unsigned long *range_count)
+{
+	unsigned long min, max;
+	unsigned long count;
+	uid_t start;
+
+	assert (range_start != NULL);
+	assert (range_count != NULL);
+
+	min = getdef_ulong ("SUB_UID_MIN", 100000UL);
+	max = getdef_ulong ("SUB_UID_MAX", 600100000UL);
+	count = getdef_ulong ("SUB_UID_COUNT", 65536);
+
+	if (min > max || count >= max || (min + count - 1) > max) {
+		(void) fprintf (stderr,
+				_("%s: Invalid configuration: SUB_UID_MIN (%lu),"
+				  " SUB_UID_MAX (%lu), SUB_UID_COUNT (%lu)\n"),
+			Prog, min, max, count);
+		return -1;
+	}
+
+	start = sub_uid_find_free_range(min, max, count);
+	if (start == (uid_t)-1) {
+		fprintf (stderr,
+		         _("%s: Can't get unique subordinate UID range\n"),
+		         Prog);
+		SYSLOG ((LOG_WARN, "no more available subordinate UIDs on the system"));
+		return -1;
+	}
+	*range_start = start;
+	*range_count = count;
+	return 0;
+}
+#else				/* !ENABLE_SUBIDS */
+extern int errno;		/* warning: ANSI C forbids an empty source file */
+#endif				/* !ENABLE_SUBIDS */
+